This study evaluates the effectiveness of a family-based psychosocial treatment program for teens with ADHD (STAND; Sibley et al., 2013, 2014) developed to be delivered in community settings. STAND is BT enhanced by Motivational Interviewing (MI) that was developed (R34 MH092466) for teens with ADHD through a stakeholder informed process. A total of 300 adolescents with ADHD will be recruited from four community mental health agencies and randomly assigned to receive STAND or Usual Care (UC) in the community agency. Therapists will be randomly assigned to deliver STAND or UC to assigned cases. STAND therapists will receive a three-day training and weekly supervision from study psychologists. STAND consists of ten 50-minute sessions delivered by therapists with community-typical levels of training and supervision. Study assessments will occur at baseline, four months post-baseline (post-treatment), and three-months post-treatment (follow-up). To test the intervention's effectiveness, the study will examine treatment effects on academic indices (school grades, parent/teacher ratings of academic functioning) and family functioning (parent/adolescent ratings). Effectiveness will also be measured through consumer perspectives (parent/adolescent ratings of satisfaction and therapeutic alliance) and agency fit (therapist competence, treatment fidelity, therapist attitude toward treatment, need for additional services, attendance, cost). To detect whether mechanisms of response are engaged by STAND in the community settings, five treatment mediators will be tested using multi-method indices: executive functioning (parent ratings, cognitive tasks, direct observation), motivation (parent/adolescent ratings, cognitive tasks), parent-teen communication (video tasks), parent academic involvement (parent report, video task), and parent readiness to change (parent report, session audio recordings). Finally we will study the conditions under which STAND effects are maximized by examining patient, practitioner, and service delivery characteristics that moderate treatment effects: billing status, ethnicity, parent/adolescent attendance, medication use, therapist training level, # of years post-training experience, caseload, setting, and time frame of delivery. This project represents the first attempt to evaluate a psychosocial treatment for teens with ADHD delivered in a community mental health setting. If successful, the public impact of STAND due to a documented effectiveness gap in this population. If STAND participants show meaningful improvements in functioning and agency fit is strong, STAND could significantly benefit the sorely underserved population of adolescents with ADHD.